Question

What is the wavelength of this light?

A beam of radiation has an energy of `2.81×10^2` kJ/mol.

Answer 1

`426` nm

Explanation:

The energy of a single radiation is
`E= (2.81 x 10^5 J/(mol))/(6.02 x 10^23 (radiation)/(mol ))=4,67 xx 10^(-19) J`
from Plank's equation
`E= hnu` , we have the frequency (`nu`) of the single radiation
`nu= E/h =(4,67 xx 10^(-19) J)/(6,63 xx 10^(-34) J xx s)=7,04 xx 10^14 s^(-1)`
from the relation
`c= lambda xx nu`
we have
`lambda =c/nu= (3 xx 10^8 m/s)/(7,04 xx 10^14 s^(-1))=4,26 xx 10^(-7) m= 426 nm`